vault backup: 2025-03-04 11:17:00

20.01. Programming/DB/MySQL.md

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+## Install MySQL
+- 下載MySQL： https://downloads.mysql.com/archives/installer/
+- 安裝
+- 安裝之後，執行MSQL Installer - Community
+    - ![[Pasted image 20210423152623.png]]
+- 選擇MySQL Server的Reconfigure
+    - ![[Pasted image 20210423152747.png]]
+- 依序設定port、帳號密碼。
+
+## Install MariaDB
+1. `sudo apt install mariadb-server`
+2. Configuring MariaDB: `sudo mysql_secure_installation`
+    這步驟會問幾個問題，大概是：
+    1.　輸入目前root的密碼
+    2.　是否要切換為unix_socket？ -> No
+    3.　要變更root的密碼嗎？-> No
+3. Testing MariaDB: `sudo systemctl status mariadb`
+4. Show version: `sudo mysqladmin version`
+
+## Syntax
+### Basic
+login as root: `mysql -u root -p`
+
+### User management
+#### Create user
+```sql
+CREATE USER 'testuser'@'localhost' IDENTIFIED BY 'test123test!';
+```
+
+#### Remove user
+```sql
+DROP USER 'testuser'@'localhost';
+```
+
+#### Grant user's permission
+Below commands grant user's permission to *CREATE* and *DROP*.
+```sql
+GRANT CREATE ON *.* TO 'testuser'@'localhost';
+GRANT DROP ON tutorial_database.* TO 'testuser'@'localhost';
+FLUSH PRIVILEGES;
+```
+
+#### Remove user's permission
+```sql
+REVOKE <permission> ON database.table FROM 'user'@'localhost';
+```
+上面命令中的`<permission>`必須替換成下面的其中一個：
+- ALL - Allow complete access to a specific database. If a database is not specified, then allow complete access to the entirety of MySQL.
+- CREATE - Allow a user to create databases and tables.
+- DELETE - Allow a user to delete rows from a table.
+- DROP - Allow a user to drop databases and tables.
+- EXECUTE - Allow a user to execute stored routines.
+- GRANT OPTION - Allow a user to grant or remove another user's privileges.
+- INSERT - Allow a user to insert rows from a table.
+- SELECT - Allow a user to select data from a database.
+- SHOW DATABASES- Allow a user to view a list of all databases.
+- UPDATE - Allow a user to update rows in a table.
+
+例如：`REVOKE CREATE ON *.* FROM 'testuser'@'localhost';`
+最後，不要忘記`FLUSH PRIVILEGES;`
+
+#### Show user's permission
+```sql
+SHOW GRANTS FOR 'testuser'@'localhost';
+```
+
+#### Change user's password
+```sql
+ALTER USER 'user-name'@'localhost' IDENTIFIED BY 'NEW_USER_PASSWORD';
+```
+
+#### View all users
+```sql
+SELECT User,Host FROM mysql.user;
+```
+
+### Database
+#### Show all databases
+```sql
+SHOW DATABASES;
+```
+
+### Create table
+The rule:
+```sql
+CREATE TABLE table_name (column_name column_type);
+```
+
+Example:
+```sql
+CREATE TABLE tutorials_tbl(
+   tutorial_id INT NOT NULL AUTO_INCREMENT,
+   tutorial_title VARCHAR(100) NOT NULL,
+   tutorial_author VARCHAR(40) NOT NULL,
+   submission_date DATE,
+   PRIMARY KEY ( tutorial_id )
+);
+```
+
+```sql
+use autostation;
+CREATE TABLE station_state(
+   id CHAR(255) NOT NULL,
+   ip CHAR(255) NOT NULL,
+   dhcp_ip CHAR(255) NOT NULL,
+   name CHAR(255) NOT NULL,
+   setupfilemd5 CHAR(255) NOT NULL,
+   setupfileversion CHAR(255) NOT NULL,
+   status CHAR(255) NOT NULL,
+   update_time DATETIME NOT NULL,
+   PRIMARY KEY ( id )
+);
+```
+
+### Insert
+The rule:
+```
+INSERT INTO <table_name> ( field1, field2,...fieldN )
+                         VALUES
+                         ( value1, value2,...valueN );
+```
+
+Example:
+```
+INSERT INTO client_state ( field1, field2,...fieldN )
+                         VALUES
+                         ( value1, value2,...valueN );
+```
+
+## 參考
+-　[Create a MySQL User on Linux via Command Line | Liquid Web](https://www.liquidweb.com/kb/create-a-mysql-user-on-linux-via-command-line/)
+-　[Grant Permissions to a MySQL User on Linux via Command Line | Liquid Web](https://www.liquidweb.com/kb/grant-permissions-to-a-mysql-user-on-linux-via-command-line/)
+-　[Remove Permissions for a MySQL User on Linux via Command Line - Liquid Web](https://www.liquidweb.com/kb/remove-permissions-for-a-mysql-user-on-linux-via-command-line/)
+-　[Remove a MySQL User on Linux via Command Line - Liquid Web](https://www.liquidweb.com/kb/remove-a-mysql-user-on-linux-via-command-line/)